Understanding DNS components

The DNS is more than just a protocol, it consists of several independent entities working together to deliver a scalable and reliable domain name database. In its simplest form, there are three core components of the DNS: the namespace, server, and resolver.

Namespace

A namespace is a structure of the DNS database. It is represented in the form of an inverted tree with its root node at the top. Each node in the tree has a label and the root node has a null label. Take a look at the following diagram:

A domain name is the sequence of labels starting from a node to the root, separated by dots. The namespace can have a maximum depth of 127 levels and domain names can be of a size not more than 255 characters in length:

Name servers

Name servers are responsible for storing information about the namespace in the form of zones. There can be multiple name servers and ones that load a complete zone are said to be authoritative for the zone. Generally, there is more than one...